Powertrain, generic · Fuel and air metering, auxiliary emission controls

P0049 Turbocharger/Supercharger A Turbine Overspeed

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

The control module has detected that turbocharger A runs above its permitted maximum speed. Engines equipped for it measure turbine speed with a dedicated sensor on the shaft; while the fault is active some systems continue with an estimated speed and reduce power. Real overspeed arises when too much exhaust energy reaches the turbine, for example because the wastegate or the turbine vanes stick closed, or because the turbocharger has to compensate for a charge-air leak or high altitude. Since a damaged turbocharger can fail completely, the cause should be found before driving on. Turbocharger B has its own code.

Likely causes

Wastegate or turbine vanes stuck closed, boost control fails
Turbocharger speed sensor or its wiring faulty
Charge-air leak forcing the turbocharger to higher speed
Engine control module or software

Symptoms

  • Check engine light on
  • Reduced power or limp mode
  • Whistling from the turbocharger
  • Risk of turbocharger damage

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–4,000
Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

turbochargerturbocharger speed sensorwastegateturbocharger vanes or wastegate

Related codes

P00C5P2579P0234P0243

References: law.cornell.edu, static.nhtsa.gov, en.wikipedia.org.